We cannot hear on the surface of the moon because

it has very low gravitational force

When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow like colours are seen. This can be explained on the basis of the phenomenon of

refraction, diffraction and transmission

A cut diamond sparkles because of its

emission of light by the diamond

absorption of light by the diamond

Kerosene oil rises up in a wick of a lantern because of

diffusion of the oil through the wick

the gravitational pull of the wick

may or may not produce sound if the amplitude of vibration is low

will produce sound which depends upon frequency

Microwave oven consumes less power due to

large frequency as well as wavelength of radiation

small frequency as well as wavelength of radiation

If you are at open- air concert and someone's head gets between you and the orchestra, you can still hear the orchestra because

the sound is reflected from the head

sound waves pass easily through a head

a head is not very large compared with the wavelength of the sound

the sound is reflected from the head

the wavelength of the sound is much smaller than the head

Bats can ascertain distance, directions, nature and size of the obstacles at night. This is possible by reflection of the emitted

ultrasonic waves from the distant objects

supersonic waves from the distant objects

Assertion (A) : Radio waves bend in a magnetic fieldReason (R) : Radio waves are electromagnetic in nature Codes :

A and R are individually true and R is the correct explanation of A

A and R are individually true, but R is not the correct explanation of A

There are three wavelengths 107 m, and 10-10 m, and 10-7 m. Find their respective names

Visible rays, Radio wave, X-rays

X - rays, Visible rays, Radio waves

Radio waves, X-rays, Visible rays

Visible rays, Radio wave, X-rays

In vacuum, the speed of light

Neither depends on its wavelength, frequency nor intensity

As a wave strikes against a wall

Its phase does not change, but velocity change

Its velocity changes and phase too changes by 180

213 + Mcqs in Sound in Physics Page 1 McqOptions

1.	Sound travels in the form of
A.	transverse waves
B.	longitudinal waves
C.	stationary waves
D.	none of above
Answer» C. stationary waves

Discussion

2.	Ultrasonics are sound waves of frequency
A.	greater than 20,000 Hz
B.	less than 10,000 Hz
C.	equal to 1000 Hz
D.	None of these
Answer» B. less than 10,000 Hz

Discussion

3.	Sound above what level (in decibel) is considered hazardous noise pollution?
A.	30 dB
B.	40 dB
C.	60 dB
D.	80 dB
Answer» E.

Discussion

4.	Richter scale is used for measuring
A.	velocity of sound
B.	intensity of light
C.	amplitude of seismic waves
D.	intensity of sound
Answer» D. intensity of sound

Discussion

5.	We cannot hear on the surface of the moon because
A.	its surface absorbs sound
B.	it has no atmosphere
C.	it has very low gravitational force
D.	None of these
Answer» C. it has very low gravitational force

Discussion

6.	Noise and music differ in their
A.	quality
B.	tone
C.	note
D.	pitch
Answer» D. pitch

Discussion

7.	Sound cannot travel though
A.	solids
B.	liquids
C.	gases
D.	vacuum
Answer» E.

Discussion

8.	When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow like colours are seen. This can be explained on the basis of the phenomenon of
A.	reflection and diuffraction
B.	reflection and transmission
C.	diffraction and transmission
D.	refraction, diffraction and transmission
Answer» E.

Discussion

9.	Sound travels fastest in
A.	vacuum
B.	liquid
C.	air
D.	metal
Answer» E.

Discussion

10.	To hear a clear echo, the minimum distance should be
A.	165 feet
B.	165 meter
C.	16.5 feet
D.	16.5 meter
Answer» E.

Discussion

11.	A cut diamond sparkles because of its
A.	hardness
B.	high refractive index
C.	emission of light by the diamond
D.	absorption of light by the diamond
Answer» C. emission of light by the diamond

Discussion

12.	Finger prints on a piece of paper may be detected by sprinkling fluorescent powder on the paper and then looking it into
A.	mercury light
B.	sunlight
C.	infrared light
D.	ultraviolet light
Answer» E.

Discussion

13.	Kerosene oil rises up in a wick of a lantern because of
A.	diffusion of the oil through the wick
B.	capillary action
C.	buoyant force of air
D.	the gravitational pull of the wick
Answer» C. buoyant force of air

Discussion

14.	A vibrating body
A.	will always produce sound
B.	may or may not produce sound if the amplitude of vibration is low
C.	will produce sound which depends upon frequency
D.	None of these
Answer» D. None of these

Discussion

15.	The audible frequency range of a human ear is
A.	20 Hz to 200 Hz
B.	2 Hz to 20 Hz
C.	200 Hz to 2000 Hz
D.	20 Hz to 20000 Hz
Answer» E.

Discussion

16.	Microwave oven consumes less power due to
A.	small frequency of radiation
B.	short wavelength of radiation
C.	large frequency as well as wavelength of radiation
D.	small frequency as well as wavelength of radiation
Answer» C. large frequency as well as wavelength of radiation

Discussion

17.	If you are at open- air concert and someone's head gets between you and the orchestra, you can still hear the orchestra because
A.	sound waves pass easily through a head
B.	a head is not very large compared with the wavelength of the sound
C.	the sound is reflected from the head
D.	the wavelength of the sound is much smaller than the head
Answer» C. the sound is reflected from the head

Discussion

18.	Bats can ascertain distance, directions, nature and size of the obstacles at night. This is possible by reflection of the emitted
A.	ultrasonic waves from the bat
B.	ultrasonic waves from the distant objects
C.	supersonic waves from the bat
D.	supersonic waves from the distant objects
Answer» B. ultrasonic waves from the distant objects

Discussion

19.	Consider the following statements with reference to X - rays 1. They produce heat when absorbed by matter 2. They are generated when fast moving electrons 3. They can penetrate through a thin sheet of aluminium. Which of the statements given above are correct ?
A.	1, 2 and 3
B.	1 and 2
C.	2 and 3
D.	1 and 3
Answer» B. 1 and 2

Discussion

20.	A pendulum having period of oscillation of 2s is taken on a planet where g is four times that on earth. The period of the pendulum would be
A.	2 s
B.	1 s
C.	4 s
D.	2
E.	s
Answer» C. 4 s

Discussion

21.	The patient is asked to drink barium sulphate (BaSO₄) for examining the stomach by X - rays because X - rays are
A.	Reflected by heavy atoms
B.	Refracted by heavy atoms
C.	Less absorbed by heavy atoms
D.	More absorbed by heavy atoms
Answer» E.

Discussion

22.	Consider the following parts of spectra 1. Visible 2. Infrared 3. Ultraviolet 4. Microwave Which one of the following is the correct sequence in which their wavelengths increase?
A.	4-3-1-2
B.	4-1-2-3
C.	3-2-1-4
D.	3-1-2-4
Answer» E.

Discussion

23.	Velocity of sound in air 1. Increases with temperature 2. Decreases with temperature 3. Increases with pressure 4. Is independent of pressure 5. Is independent of temperature
A.	only 1 and 2 are true
B.	only 2 and 4 are true
C.	only 1 and 3 are true
D.	only 1 and 4 are true
Answer» E.

Discussion

24.	How does the speed V of sound in air depend on atmospheric pressure P ?
A.	V P
B.	V P
C.	V P
D.	V P
Answer» D. V P

Discussion

25.	The length of the pendulum is doubled and the mass of its bob is halved. Its time period would
A.	Become double
B.	Become half
C.	Become
D.	times
E.	Remain the same
Answer» D. times

Discussion

26.	When a wave goes from one level to another, there is a change in the (i) Velocity (ii) Amplitude (iii) Frequency (iv) Wavelength Choose the correct answer
A.	Only (i)
B.	(i) and (ii)
C.	(i), (ii) and (iv)
D.	All of them
Answer» D. All of them

Discussion

27.	Consider the following electromagnetic waves 1. X - rays 2. y - rays 3. Microwaves 4. radio waves What is the correct sequence in the order of their increasing energy ?
A.	4,3, 1 and 2
B.	1, 3, 2 and 4
C.	4, 2, 1 and 3
D.	1, 4, 3 and 2
Answer» B. 1, 3, 2 and 4

Discussion

28.	Consider the following statement 1. Microwaves are used in radar system for air craft navigation 2. Microwave ovens are used for cooking purposes 3. A radar using microwave can help in detecting the speed of tennis ball, cricket ball, automobile while in motion. Which of these statements are correct?
A.	1 and 2
B.	2 and 3
C.	1 and 3
D.	1, 2 and 3
Answer» E.

Discussion

29.	If T is the reverberation time of an auditorium of volume V then
A.	T V
B.	T 1 / V
C.	T V
D.	T 1 / V
Answer» B. T 1 / V

Discussion

30.	Consider the following statements 1. Light of longer wavelength is scattered much more than the light of shorter wavelength. 2. The speed of visible light in water is 0.95 times the speed in vacuum. 3. Radio waves are produced by rapidly oscillating electrical currents. 4. To detect the overspending vehicles, police use the Doppler effect of reflected short radio waves Which of these statements are correct?
A.	1 and 2
B.	1 and 3
C.	2 and 4
D.	3 and 4
Answer» E.

Discussion

31.	The speed of sound in air at S.T.P. is 300 m / s. If the air pressure becomes double, the temperature remaining the same, the speed of sound would
A.	1200 m / s
B.	600 m / s
C.	300 m / s
D.	300
E.	m / s
Answer» D. 300

Discussion

32.	Assertion (A) : Radio waves bend in a magnetic field Reason (R) : Radio waves are electromagnetic in nature Codes :
A.	A and R are individually true and R is the correct explanation of A
B.	A and R are individually true, but R is not the correct explanation of A
C.	A is true, but R is false
D.	A is false, but R is true
Answer» E.

Discussion

33.	The velocity of sound in air is affected by change in the 1. Atmospheric pressure 2. Moisture content of air 3. Temperature of air 4. Composition of air Choose the correct answer
A.	1 and 2
B.	1, 3 and 4
C.	1, 2 and 3
D.	2, 3 and 4
Answer» E.

Discussion

34.	Which of the following statements about electromagnetic wave is / are correct ? 1. X - rays in vacuum travel faster than light waves in vacuum. 2. The energy of X - rays photon is greater than that of a light photon. 3. Light can be polarised but X - rays cannot. Codes
A.	1 and 2
B.	2 and 3
C.	1, 2 and 3
D.	Only 2
Answer» E.

Discussion

35.	Consider the following statements : 1. X - rays show transverse wave characteristics 2. X - rays can eject electrons from certain metal surfaces 3. X - rays of 0.1 A are harder than X - rays of 0.2 A Which of the statements given above is / are correct ?
A.	1 only
B.	1 and 2 only
C.	2 an 3 only
D.	1, 2 and 3
Answer» E.

Discussion

36.	There are three wavelengths 10⁷ m, and 10^-10 m, and 10^-7 m. Find their respective names
A.	X - rays, Visible rays, Radio waves
B.	Radio waves, X-rays, Visible rays
C.	Visible rays, Radio wave, X-rays
D.	None of the above
Answer» C. Visible rays, Radio wave, X-rays

Discussion

37.	Consider the following parts of spectra 1. Visible 2. Infrared 3. Ultraviolet 4. Microwave Which one of the following is the correct sequence in which their wavelength increase ?
A.	4 - 3 - 1 - 2
B.	4 - 1 - 2 - 3
C.	3 - 2 - 1 - 4
D.	3 - 1 - 2 - 4
Answer» E.

Discussion

38.

Match List - I (Electromagnetic wave) with List - II (Discoverer) and select the correct answer using the codes given below
List-I List-II
F Infrared waves 1. W. Roentgen
G Ultraviolet rays 2. Newton
H X - rays 3. Herschell
J Visible rays 4. Ritter
Code
F G H J
A. 1 2 3 4
B. 3 4 1 2
C. 3 4 2 1
D. 4 3 1 2

A.

B.

C.

D.

Answer» C. C.

Discussion

39.

Match List - I (Eletromagnetic radiation) with List - II (Approximate wavelength in metres) and select the correct answer using the codes given below the lists
List-I List-II
F Infrared radiation 1. 10^-12
G X - rays 2. 10^-5
H Ultraviolet radiation 3. 10^-10
J Gamma rays 4. 10^-8
Codes :
F G H J
A. 2 3 4 1
B. 1 4 3 2
C. 1 3 4 2
D. 2 4 3 1

A.

B.

C.

D.

Answer» B. B.

Discussion

40.	In vacuum, the speed of light
A.	Depends on its wavelength
B.	Depends on its frequency
C.	Depends on its intensity
D.	Neither depends on its wavelength, frequency nor intensity
Answer» E.

Discussion

41.

Match List - I (type of electromagnetic radiation ) with List - II (corresponding wavelength ) and select the correct answer using the codes given below
List-I List-II
F Radio waves 1. 4x10^-7 - 7x10^-7 m
G Uitraviolet waves 2. 10^-11 - 10^-9 m
H Visible light 3. 10^-6 - 10^{-3 m}
J X - rays 4. 10^-3 - 10^-5 m
5. 10^-9 - 10⁷ m
Code
F G H J
A. 3 2 4 5
B. 4 5 1 2
C. 3 5 4 2
D. 4 2 1 5

A.

B.

C.

D.

Answer» C. C.

Discussion

42.	Consider the following two statements regarding a linearly polarized plane electromagnetic wave 1. The electric field and the magnetic field have equal average values 2. The electric energy and magnetic energy have equal average values
A.	1 is false but 2 is true
B.	both 1 and 2 are true
C.	2 is false but 1 is true
D.	both 1 and 2 are false
Answer» C. 2 is false but 1 is true

Discussion

43.	Consider the following statements 1. sound waves are elastic waves 2. In sound waves, the vibrations are perpendicular to the direction in which the wave travels. Which of these statement is / are correct ?
A.	1 only
B.	2 only
C.	Both 1 and 2
D.	Neither 1 nor 2
Answer» B. 2 only

Discussion

44.	As a wave strikes against a wall
A.	Its phase changes by 180
B.	, but velocity does not change
C.	Its phase does not change, but velocity change
D.	Its velocity changes and phase too changes by 180
E.	None of the above
Answer» B. , but velocity does not change

Discussion

45.	Consider the following statements : X - rays 1. Can pass through thin sheets of aluminium 2. Can be deflected by magnetic field 3. Move with a velocity less than the velocity of ultraviolet rays in vacuum Which of the statement given above is / are correct ?
A.	1, 2 and 3
B.	1 only
C.	2 and 3 only
D.	1 and 2 only
Answer» C. 2 and 3 only

Discussion

46.	Consider the following statements 1. X - rays show transverse wave characteristics 2. X - rays can eject electrons from certain metal surfaces 3. X - rays of 0. 1 A are harder than X - rays of 0.2 A. Which of the statements given above is / are correct ?
A.	1 only
B.	1 and 2 only
C.	2 and 3 only
D.	1, 2 and 3
Answer» E.

Discussion

47.

Match List - I (frequency range) with List - II (Uses) and select the correct answer
List-I List-II
F 54 MHz to 890 MHz 1. UHF band
G 1710 kHz to 54 MHz 2. Television waves
H 88 MHz to 108 MHz 3. Short wave
J 300 MHz to 30,000MHz 4. FM radio
Code
F G H J
A. 1 2 3 4
B. 2 3 4 1
C. 4 3 2 1
D. 3 2 1 4

A.

B.

C.

D.

Answer» C. C.

Discussion

48.	Two waves are given by y₁ = a sin ( t - kx ) and y₂ = a cos ( t - kx). The phase difference between them is
A.	/ 4
B.	/ 6
C.	/ 8
D.	/ 2
Answer» E.

Discussion

49.	Consider the following statements 1. A geo-stationary satellite is at an approximate height of 10,000 km 2. FM transmission of music is a very good quality because the atmospheric or man made noises which are generally frequency variations can do little harm. Which of the statements give above is / are correct?
A.	1 only
B.	2 only
C.	Both 1 and 2
D.	Neither 1 nor 2
Answer» C. Both 1 and 2

Discussion

50.	Some common mediums in which speed of sound of sound? 1. Air 2. Steel 3. Copper 4. Water What is the correct increasing order of the speed of sound ?
A.	1 < 4 < 2 < 3
B.	4 < 1 < 2 < 3
C.	1 < 4 < 3 < 2
D.	4 < 1 < 3 < 2
Answer» D. 4 < 1 < 3 < 2

Discussion

Explore topic-wise MCQs in Physics.

Sound travels in the form of

Ultrasonics are sound waves of frequency

Sound above what level (in decibel) is considered hazardous noise pollution?

Richter scale is used for measuring

We cannot hear on the surface of the moon because

Noise and music differ in their

Sound cannot travel though

When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow like colours are seen. This can be explained on the basis of the phenomenon of

Sound travels fastest in

To hear a clear echo, the minimum distance should be

A cut diamond sparkles because of its

Finger prints on a piece of paper may be detected by sprinkling fluorescent powder on the paper and then looking it into

Kerosene oil rises up in a wick of a lantern because of

A vibrating body

The audible frequency range of a human ear is

Microwave oven consumes less power due to

If you are at open- air concert and someone's head gets between you and the orchestra, you can still hear the orchestra because

Bats can ascertain distance, directions, nature and size of the obstacles at night. This is possible by reflection of the emitted

Consider the following statements with reference to X - rays 1. They produce heat when absorbed by matter2. They are generated when fast moving electrons 3. They can penetrate through a thin sheet of aluminium.Which of the statements given above are correct ?

A pendulum having period of oscillation of 2s is taken on a planet where g is four times that on earth. The period of the pendulum would be

The patient is asked to drink barium sulphate (BaSO4) for examining the stomach by X - rays because X - rays are

Consider the following parts of spectra1. Visible2. Infrared 3. Ultraviolet4. MicrowaveWhich one of the following is the correct sequence in which their wavelengths increase?

Velocity of sound in air1. Increases with temperature2. Decreases with temperature3. Increases with pressure 4. Is independent of pressure5. Is independent of temperature

How does the speed V of sound in air depend on atmospheric pressure P ?

The length of the pendulum is doubled and the mass of its bob is halved. Its time period would

When a wave goes from one level to another, there is a change in the(i) Velocity(ii) Amplitude(iii) Frequency (iv) Wavelength Choose the correct answer

Consider the following electromagnetic waves1. X - rays2. y - rays3. Microwaves4. radio wavesWhat is the correct sequence in the order of their increasing energy ?

Consider the following statement1. Microwaves are used in radar system for air craft navigation2. Microwave ovens are used for cooking purposes3. A radar using microwave can help in detecting the speed of tennis ball, cricket ball, automobile while in motion.Which of these statements are correct?

If T is the reverberation time of an auditorium of volume V then

The speed of sound in air at S.T.P. is 300 m / s. If the air pressure becomes double, the temperature remaining the same, the speed of sound would

Assertion (A) : Radio waves bend in a magnetic fieldReason (R) : Radio waves are electromagnetic in nature Codes :

The velocity of sound in air is affected by change in the 1. Atmospheric pressure2. Moisture content of air3. Temperature of air4. Composition of airChoose the correct answer

Which of the following statements about electromagnetic wave is / are correct ?1. X - rays in vacuum travel faster than light waves in vacuum.2. The energy of X - rays photon is greater than that of a light photon.3. Light can be polarised but X - rays cannot.Codes

Consider the following statements :1. X - rays show transverse wave characteristics 2. X - rays can eject electrons from certain metal surfaces3. X - rays of 0.1 A are harder than X - rays of 0.2 A Which of the statements given above is / are correct ?

There are three wavelengths 107 m, and 10-10 m, and 10-7 m. Find their respective names

Consider the following parts of spectra1. Visible2. Infrared3. Ultraviolet4. MicrowaveWhich one of the following is the correct sequence in which their wavelength increase ?

Match List - I (Electromagnetic wave) with List - II (Discoverer) and select the correct answer using the codes given belowList-IList-IIF Infrared waves1.W. RoentgenG Ultraviolet rays2.NewtonH X - rays 3.HerschellJ Visible rays4.RitterCodeF G H J A. 1234B. 3412C. 3421D. 4312

In vacuum, the speed of light

Consider the following two statements regarding a linearly polarized plane electromagnetic wave1. The electric field and the magnetic field have equal average values2. The electric energy and magnetic energy have equal average values

Consider the following statements1. sound waves are elastic waves2. In sound waves, the vibrations are perpendicular to the direction in which the wave travels.Which of these statement is / are correct ?

As a wave strikes against a wall

Consider the following statements : X - rays1. Can pass through thin sheets of aluminium2. Can be deflected by magnetic field3. Move with a velocity less than the velocity of ultraviolet rays in vacuumWhich of the statement given above is / are correct ?

Consider the following statements1. X - rays show transverse wave characteristics2. X - rays can eject electrons from certain metal surfaces3. X - rays of 0. 1 A are harder than X - rays of 0.2 A .Which of the statements given above is / are correct ?

Match List - I (frequency range) with List - II (Uses) and select the correct answerList-IList-IIF 54 MHz to 890 MHz1.UHF bandG 1710 kHz to 54 MHz2.Television wavesH 88 MHz to 108 MHz 3.Short wave J 300 MHz to 30,000MHz4.FM radioCodeF G H J A. 1234B. 2341C. 4321D. 3214

Two waves are given by y1 = a sin ( t - kx ) and y2 = a cos ( t - kx). The phase difference between them is

Some common mediums in which speed of sound of sound?1. Air2. Steel3. Copper4. WaterWhat is the correct increasing order of the speed of sound ?

Consider the following statements with reference to X - rays
1. They produce heat when absorbed by matter
2. They are generated when fast moving electrons
3. They can penetrate through a thin sheet of aluminium.
Which of the statements given above are correct ?

The patient is asked to drink barium sulphate (BaSO₄) for examining the stomach by X - rays because X - rays are

Consider the following parts of spectra
1. Visible
2. Infrared
3. Ultraviolet
4. Microwave
Which one of the following is the correct sequence in which their wavelengths increase?

Velocity of sound in air
1. Increases with temperature
2. Decreases with temperature
3. Increases with pressure
4. Is independent of pressure
5. Is independent of temperature

When a wave goes from one level to another, there is a change in the
(i) Velocity
(ii) Amplitude
(iii) Frequency
(iv) Wavelength
Choose the correct answer

Consider the following electromagnetic waves
1. X - rays
2. y - rays
3. Microwaves
4. radio waves
What is the correct sequence in the order of their increasing energy ?

Assertion (A) : Radio waves bend in a magnetic field
Reason (R) : Radio waves are electromagnetic in nature
Codes :

The velocity of sound in air is affected by change in the
1. Atmospheric pressure
2. Moisture content of air
3. Temperature of air
4. Composition of air
Choose the correct answer

Which of the following statements about electromagnetic wave is / are correct ?
1. X - rays in vacuum travel faster than light waves in vacuum.
2. The energy of X - rays photon is greater than that of a light photon.
3. Light can be polarised but X - rays cannot.
Codes

Consider the following statements :
1. X - rays show transverse wave characteristics
2. X - rays can eject electrons from certain metal surfaces
3. X - rays of 0.1 A are harder than X - rays of 0.2 A
Which of the statements given above is / are correct ?

There are three wavelengths 10⁷ m, and 10^-10 m, and 10^-7 m. Find their respective names

Consider the following parts of spectra
1. Visible
2. Infrared
3. Ultraviolet
4. Microwave
Which one of the following is the correct sequence in which their wavelength increase ?

Consider the following two statements regarding a linearly polarized plane electromagnetic wave
1. The electric field and the magnetic field have equal average values
2. The electric energy and magnetic energy have equal average values

Consider the following statements
1. sound waves are elastic waves
2. In sound waves, the vibrations are perpendicular to the direction in which the wave travels.
Which of these statement is / are correct ?

Consider the following statements : X - rays
1. Can pass through thin sheets of aluminium
2. Can be deflected by magnetic field
3. Move with a velocity less than the velocity of ultraviolet rays in vacuum
Which of the statement given above is / are correct ?

Consider the following statements
1. X - rays show transverse wave characteristics
2. X - rays can eject electrons from certain metal surfaces
3. X - rays of 0. 1 A are harder than X - rays of 0.2 A.
Which of the statements given above is / are correct ?

Match List - I (frequency range) with List - II (Uses) and select the correct answer
List-I List-II
F 54 MHz to 890 MHz 1. UHF band
G 1710 kHz to 54 MHz 2. Television waves
H 88 MHz to 108 MHz 3. Short wave
J 300 MHz to 30,000MHz 4. FM radio
Code
F G H J
A. 1 2 3 4
B. 2 3 4 1
C. 4 3 2 1
D. 3 2 1 4

Two waves are given by y₁ = a sin ( t - kx ) and y₂ = a cos ( t - kx). The phase difference between them is

Some common mediums in which speed of sound of sound?
1. Air
2. Steel
3. Copper
4. Water
What is the correct increasing order of the speed of sound ?